I've got an issue with my 93 series 6 jap spec manual fully factory apart from muffler, when the car is cold or waming up it runs perfectly, then it hits full operating temperature it won't accelerate under any load at all just backfires like hell and cuts all power. If I'm VERY gentle on the peddle it will go all the way through the rev range it's like as soon as there is bost pressure it cuts fuel, if I turn key off and back on again when running it's runs perfectly untill l I come to a low speed and it then start cutting out again. Car has a new fuel pump and fuel filter have checked all vacuum lines and MAP sensor, checked the tps all within spec, have swaped ecu with another factory one...anyone out there with any thoughts on what could be

 

pull dem codes, man

 

Low fuel pressure. When the pump was replaced, I bet the o ring on the feed pipe was not. You would do good to go away with that connection method entirely and switch to a piece of SUBMERSIBLE hose. We have a video on how to do this on our YouTube page.

 

have tried pully codes and doesn't give me anything no lights im pretty sure the rhd jap cars don't have an engine light either, they used the heat light from what I've been reading but still get nothing

 

“no codes” is also useful information.

 

Have just looked into that, o ring is in good shape and have replaced anyway but will probably do that modification you are talking about

 

I replaced the fuel filter again its only dun 10k kms but thought it might have sucked up some crap, as well as the fuel line upgrade above. Took the car for a drive ran perfectly for a good 10min, parked it up for 10min then it started hesitating again, surly someone out there has run into the same thing?

 

Just a guess, but marginal ignition coils have been known to fail when heat-soaked.

 

Sounds like limp mode to me. You have a boost gauge, if you reach atmospheric pressure and it seems like it fuel cuts, that's probably it. The real question is what is causing your car to enter limp mode. afaik if it can't detect the OMP it does this, if it feels like it can't control boost it does this, all it takes is a few overboost moments and it will re-engage the limp and try to keep the car in vacuum.

 

Do you have a wideband O2 gauge? My car has had standalone ECUs on it for a long time now, so I've always been able to rely on datalogs when troubleshooting. I've occasionally done dumb things that resulted in the engine running lean, and it's surprising how many fuel system problems might go unnoticed without a wideband O2 gauge to measure that the fuel mixture is dangerously lean (which is dangerously hot in boost). In short, I agree that your problem might be a very major fuel problem, or an ignition problem, or the ECU is detecting something and intentionally cutting fuel and spark as a limiter.